The word "俄国" is formed by combining the character "俄", which serves as an abbreviated phonetic representation derived from the full transliteration "俄罗斯" (Èluósī) for "Russia", with the character "国" meaning "country" or "nation". This structure creates a concise and commonly used term for Russia in Chinese, where the first part captures the essential sound or identity of the foreign name, and the second part categorizes it as a sovereign state.